Tests and Procedures

Ketone Bodies (Blood)

Does this test have other names?

Ketones, serum; ketones, blood

What is this test?

This blood test measures ketones, a byproduct of digestion, in your blood. When you have a high level of ketones in your blood, it's called diabetic ketoacidosis (DKA). DKA is a complication of diabetes that can be fatal if it's not treated.

When you have diabetes, your body doesn't make enough insulin, a hormone that regulates the metabolism of fat and carbohydrates. Or it can't properly use insulin to break down the food you eat. When your body doesn't have enough insulin, it breaks down fat for energy instead of glucose, or sugar. The breakdown of fat produces ketones, which can build up in your blood and spill over into your urine if your diabetes is not under control. If your ketone levels are too high, it could cause you to go into a diabetic coma.

Why do I need this test?

You might have this test if you have symptoms of DKA. These include extreme thirst, tiredness, vomiting, trouble breathing, fruity odor on your breath, high blood sugar levels, and high levels of ketones in your urine. You can test for ketones in your urine with test strips.

What other tests might I have along with this test?

Your doctor might order blood glucose levels to see if your diabetes is out of control. You might also have a urine test to check for ketones in your urine.

Your doctor also might order an electrocardiogram, or EKG, which checks your heart's electrical activity. DKA can affect the heart.

What do my test results mean?

A lab test result may be affected by many things, including the method the laboratory uses to do the test. If your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

A normal test result is negative and means you have no ketone bodies in your blood. If you test positive for ketones, it could mean your diabetes is not under control. You could have DKA.

Some people who are starving also test positive for ketones.

Ketone bodies in the blood can be a sign of alcoholism, too.

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use. Some, such as diuretics and blood pressure medicines, can lead to a false-positive ketone test.

Certain diets, such as a high-protein diet or a one that is high in fat and low in carbohydrates, also can cause increased ketones in your blood. Drinking large amounts of alcohol also can affect your test results.

You might also have a high level of ketones in your blood if you have diabetes and you're sick with a cold or the flu.